321 research outputs found
Modular switched reluctance machines to be used in automotive applications
In the last decades industry, including also that of electrical machines and drives, was pushed near to its limits by the high market demands and fierce competition. As a response to the demanding challenges, improvements were made both in the design and manufacturing of electrical machines and drives. One of the introduced advanced technological solutions was the modular construction. This approach enables on a hand easier and higher productivity manufacturing, and on the other hand fast repairing in exploitation. Switched reluctance machines (SRMs) are very well fitted for modular construction, since the magnetic insulation of the phases is a basic design requirement. The paper is a survey of the main achievements in the field of modular electrical machines, (especially SRMs), setting the focus on the machines designed to be used in automotive applications
Design of segmental rotor and non-overlap windings in single-phase fefsm for low torque high speed applications
In this research, a new structure of single-phase field excitation flux switching motor
(FEFSM) using segmental rotor structure and non-overlap windings arrangement is
proposed in order to overcome the drawbacks of low torque and small power
performances due to their longer flux path in the single-phase FEFSM using salient
rotor structure and overlap windings arrangement. The objectives of this study are to
design, analyse and examine performance of the proposed motor, to optimize the
proposed motor for optimal performances, and to develop the proposed motor
prototype for experimental performance validation. The design and analyses thru 2Dfinite
element analysis (FEA) is conducted using JMAG Designer version 15, while
deterministic optimization method is applied in design optimization process. To
validate the 2D-FEA results, the motor prototype is developed and tested
experimentally. Based on various rotor poles analysis, a combination of 12 pole 6 pole
(12S-6P) has been selected as the best design due to their highest torque and power
capability of 0.91 Nm and 277.4 W, respectively. Besides, the unbalance armature
magnetic flux of the proposed FEFSM using segmental rotor has been resolved by
using segmental rotor span refinement. The balanced armature magnetic flux
amplitude ratio obtained is 1.002, almost 41.2% reduction from the initial design. In
addition, the optimized motor has increased maximum torque and power by 80.25%
to 1.65 Nm, and 43.6% to 398.6W, respectively. Moreover, copper loss of the
optimized design has decreased by 9.7%%, hence increasing the motor efficiency of
25.3%. Finally, the measured results obtained from the prototype machine has
reasonable agreement with FEA results, proving their prospect to be applied for
industrial and home appliances
Drive control and real-time simulation for switched reluctance motor in a fuel cell power system.
Switched Reluctance Motor (SRM) drive is considered as a possible alternative to other conventional variable-speed drives because of several advantages [1], [2]. However, in order for the performance of a switched reluctance motor drive to suit several applications, it has to be tailored through appropriate control. Rotor position sensing is an integral part of SRM control because of the nature of torque production. Sensorless control reduces overall cost and dimension of the drive in addition to improving reliability. In this thesis, an Inductance Model Based Sensorless [8] Switched Reluctance Motor is used to design the drive controller for SRM. A hysteresis current controller and a speed controller were implemented to produce smooth torque and a stable speed for SRM. In addition, the do power supply for the SRM was derived from Fuel Cell Stack rather than from batteries or from utility lines through a front-end diode rectifier. In this research, first, the current controller and the speed controller are developed and connected to the Inductance Based Sensorless SRM model with the Fuel Cell Stack model and an offline simulation using Matlab/Simulink is obtained. A detailed computer model of the SRM control drive connected to the Fuel Cell stack model is developed in which the design of the proposed controller scheme is verified. As a next major step, a Real-Time simulation was obtained for the model using Opal-RT platform, and a comparison between the offline simulation results and real time simulation results is developed. As a final step, the characteristics of the SRM Inductance model, Controller model, and the Fuel Cell stack model are studied in detail, which is required in order to use them in future applications.Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .S246. Source: Masters Abstracts International, Volume: 43-05, page: 1783. Adviser: X. Chen. Thesis (M.A.Sc.)--University of Windsor (Canada), 2004
Embedded Sensors and Controls to Improve Component Performance and Reliability Conceptual Design Report
The objective of this project is to demonstrate improved reliability and increased performance made possible by deeply embedding instrumentation and controls (I&C) in nuclear power plant (NPP) components and systems. The project is employing a highly instrumented canned rotor, magnetic bearing, fluoride salt pump as its I&C technology demonstration platform. I&C is intimately part of the basic millisecond-by-millisecond functioning of the system; treating I&C as an integral part of the system design is innovative and will allow significant improvement in capabilities and performance. As systems become more complex and greater performance is required, traditional I&C design techniques become inadequate and more advanced I&C needs to be applied. New I&C techniques enable optimal and reliable performance and tolerance of noise and uncertainties in the system rather than merely monitoring quasistable performance. Traditionally, I&C has been incorporated in NPP components after the design is nearly complete; adequate performance was obtained through over-design. By incorporating I&C at the beginning of the design phase, the control system can provide superior performance and reliability and enable designs that are otherwise impossible. This report describes the progress and status of the project and provides a conceptual design overview for the platform to demonstrate the performance and reliability improvements enabled by advanced embedded I&C
Vehicle electrification: technologies, challenges and a global perspective for smart grids
Nowadays, due to economic and climate concerns, the private transportation sector is shifting for the vehicle electrification, mainly supported by electric and hybrid plug-in vehicles. For this new reality, new challenges about operation modes are emerging, demanding a cooperative and dynamic operation with the electrical power grid, guaranteeing a stable integration without omitting the power quality for the grid-side and for the vehicle-side. Besides the operation modes, new attractive and complementary technologies are offered by the vehicle electrification in the context of smart grids, which are valid for both on-board and off-board systems. In this perspective, this book chapter presents a global perspective and deals with challenges for the vehicle electrification, covering the key technologies toward a sustainable future. Among others, the flowing topics are covered: (1) Overview of power electronics structures for battery charging systems, including on-board and off-board systems; (2) State-of-the-art of communication technologies for application in the context of vehicular electrification, smart grids and smart homes; (3) Challenges and opportunities concerning wireless power transfer with bidirectional interface to the electrical grid; (4) Future perspectives about bidirectional power transfer between electric vehicles (vehicle-to-vehicle operation mode); (5) Unified technologies, allowing to combine functionalities of a bidirectional interface with the electrical grid and motor driver based on a single system; and (6) Smart grids and smart homes scenarios and accessible opportunities about operation modes.Fundação para a Ciência e Tecnologia (FCT
Online sensorless position estimation for switched reluctance motors using one current sensor
This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme
Online sensorless position estimation for switched reluctance motors using one current sensor
This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme
Rotor Position Identification for Brushless DC motor
Permanent magnet BLDC motors are characterized by a central magnetic core, called the rotor, and fixed electric coils (usually six) equally spaced in a ring around the core, called the stator. Motor movement is controlled by alternately energizing and de-energizing the stator coils to create a rotating magnetic field that propels the rotor. In order for this process to work correctly, BLDC motors required a technology called electronic commutation, in which the coil currents must be very carefully synchronized to rotor position to ensure that the rotating field is correctly aligned with the permanent magnetic field in the rotor. Usually rotor position is measured by external sensors such as Hall-effect sensors and optical encoders and these external sensors increase the system cost and reduces reliability. In order to control the price and make it more reliable this thesis propose to infer the rotor position from voltage and current measurement of motor.
The most common approaches to sensorless control are based on the measurement of the electromotive force (back-EMF), that is induced by the rotor motion. As the back-EMF is nearly zero at very low speed and at stationary position, and can not be measured. Therefore a separate algorithm is required for start-up and control at low speed. The other method of sensorless control involves the inference of rotor position from the variation in inductance caused by rotor position. This thesis presents a prototype system for sensorless control of BLDC motors over the entire speed range of the motor, including stall (zero speed) conditions using the voltage and current signals from the motor
Англійська мова для студентів електромеханічних спеціальностей
Навчальний посібник розрахований на студентів напряму підготовки
6.050702 Електромеханіка. Містить уроки, що структуровані за тематичними
розділами, граматичний коментар, короткі англо-український і українсько-
англійський словники та додатки, які спрямовані на закріплення загальних
навичок володіння англійською мовою. Акцентований на ɨсобливості
термінології, що застосовується у науково-технічній галузі, зокрема, в
електромеханіці та виконання запропонованих завдань, що буде сприяти
формуванню навичок перекладу з англійської та української мов, сприйняттю
письмової та усної англійської мови, вмінню письмового викладення
англійською мовою науково-технічних та інших текстів під час професійної
діяльності, спілкуванню з професійних та загальних питань тощо
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